The present invention relates to a tennis ball collecting pick-up and propelling system and more particularly to a ball-propelling device for automatically retrieving, loading and then propelling tennis balls in a sequence over a wide range of directions and trajectories.
Heretofore, tennis instruction has generally been provided on a conventional tennis court with the instructor or an assistant positioned in the back court on one side of the net to hit balls across the net to the student. Ball-propelling devices have been proposed for propelling a magazine of balls in sequence, but with such devices the trajectory of the ball is determined by pointing the entire device and fixing the speed of the ball. Such devices permit practice on a given stroke for a limited period of time, until the magazine is emptied. The balls must then be manually retrieved and loaded into the magazine. The device can then be positioned to propel the ball on the same or another given trajectory for additional practice. This type of instruction is suitable for beginners, in that it limits the practice to a single stroke per magazine, but the constant speed and trajectory of the ball is monotonous and of limited instructional value to an intermediate or advance player. In addition, a substantial percentage of the overall time is devoted to retrieving the balls and reloading the magazine.